A variety of implantable medical devices that deliver electrical stimulation therapy and/or monitor physiological signals have been proposed. Some implantable medical devices may employ one or more elongated electrical leads and/or sensors. Such implantable medical devices may deliver electrical stimulation therapy to the heart, muscle, nerve, brain, stomach, or other organs. In some cases, implantable medical devices deliver electrical stimulation therapy and/or sense physiological signals via one or more electrodes or sensor elements. For example, stimulation electrodes, sensing electrodes or other sensor elements may be included as part of, or carried by, one or more elongated implantable medical leads. Implantable medical leads may be configured to allow electrodes or sensors to be positioned at desired locations for delivery of stimulation or sensing of biomedical signals. For example, electrodes or sensors may be located at a distal portion of a lead. A proximal portion of the lead may be coupled to an implantable medical device housing, which may contain electronic circuitry such as electrical stimulation generation circuitry and/or sensing circuitry.